检索结果-内蒙古大学图书馆

IET International Radar Conference (IRC 2023)

作者： Yi Zhou Ying Zhou Hui Ma Shenghua Zhou Yujie Zhang Haoran Sun Xue Wang Lin Liu Hongwei Liu National Laboratory of Radar Signal Processing Xidian University Xi'an People's Republic of China Beijing Institute of Remote-sensing Equipment Science and Technology on Millimeter-wave Laboratory Beijing People's Republic of China Institute of Information Sensing Xidian University Xi'an People's Republic of China

ISBN: (数字)9781837240982

This paper investigates the feasibility of observing the satellite by its own transmitted signals. The system is a special type of the passive radar (PR) using the self-multipath signal (SMS) on satellites. Firstly, the geometry of the SMS-based PR (SMS-PR) is formulated and analysed, and then the direct signals containing self-multipath are modelled. Secondly, the in-pulse matched filtering and the direct-path cancellation are individually considered and corresponding processing algorithms are given. Thirdly, the process algorithms are proposed of the SMS-PR imaging of the satellite, based on the inverse synthetic aperture radar (ISAR) and the orthogonal matching pursuit (OMP). Finally is the post-processing of the proposed scheme is verified by the simulation results. In addition, the paper analyses also the conditions guaranteeing the successful imaging.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Controlling auto-focusing chirped perfect Laguerre-Gaussian beam to mitigate crosstalk in atmospheric turbulence

引用

Optical and Quantum Electronics 2025年第4期57卷 1-11页

作者： Ma, Yangbin Wang, Xinguang Shen, Yangbo Zhao, Ben Wang, Le Zhao, Shengmei College of Science Nanjing University of Posts and Telecommunications Wenyuan Road Jiangsu Nanjing210023 China Jiangsu Engineering Research Center of Communication and Network Technology Nanjing University of Posts and Telecommunications Wenyuan Road Jiangsu Nanjing210023 China Portland Institute Nanjing University of Posts and Telecommunications Wenyuan Road Jiangsu Nanjing210023 China School of Communications and Information Engineering Nanjing University of Posts and Telecommunications Wenyuan Road Jiangsu Nanjing210023 China Institute of Signal Processing and Transmission Nanjing University of Posts and Telecommunications New model road Jiangsu Nanjing210003 China Nanjing University of Posts and Telecommunications New model road Jiangsu Nanjing210003 China National Laboratory of Solid State Microstructures Nanjing University Hankou Road Jiangsu Nanjing210093 China

Auto-focusing beams can effectively mitigate orbital angular momentum (OAM) crosstalk in atmospheric turbulence. In this paper, we focus on the effect of the chirp factor on the crosstalk mitigation of chirped perfect Laguerre-Gaussian beam (CPLGB) based on the propagation model of CPLGB. The results demonstrate that a positive first-order chirp factor can significantly promote the auto-focusing of CPLGB, and increasing it can effectively mitigate the intermodal crosstalk of OAM modes in atmospheric turbulence, whereas a positive second-order chirp factor has a relatively weak effect on them. By comparing with Bessel Gaussian beam, perfect Laguerre-Gaussian beam, and perfect optical vortex beam, the CPLGB shows superior turbulence resistance when transmitted in atmospheric turbulence. Our results will be useful for optimizing the performance of free-space optical (FSO) communication systems with CPLGBs. © The Author(s), under exclusive licence to Springer science+Business Media, LLC, part of Springer Nature 2025.

关键词： Gaussian beams

来源：评论

学校读者我要写书评

暂无评论

Attentive Feature Focusing for Person Search by Natural Language 18th

Attentive Feature Focusing for Person Search by Natural La...

引用

18th International Forum of Digital Multimedia Communication, IFTC 2021

作者： Pan, Renjie Yang, Hua Yang, Xinxin Xiaodong, Mao Ye, Long Pan, Da The Institute of Image Communication and Network Engineering Department of Electronic Engineering Shanghai Jiao Tong University Shanghai China Shanghai Key Laboratory of Digital Media Processing and Transmission Shanghai Jiao Tong University Shanghai China Science and Technology Department of Shanghai Public Security Bureau Shanghai China State Key Laboratory of Media Convergence and Communication Communication University of China Beijing100024 China

ISBN: (纸本)9789811922657

Cross-modal Retrieval has made great improvement since social media and artificial intelligence is gradually changing our life style. Human interaction is no longer limited to a single mode. Cross-modal retrieval brings greater portability to users. Extracting more sufficient feature from multimedia data and better fusing the feature have become the focus of academic research. In response to these two issues, this paper applies deep learning as the foundation for person search by natural language, combining CNN and Transformer. Meanwhile, we utilize BERT, the most effective feature extraction network in Natural Language processing and proposed a network architecture using attention mechanism. The framework is divided into a global branch and a fine-grained branch. At the same time, a human parsing network is designed to classify different parts of the characters to obtain feature representation in attribute level. In the visual-textual alignment, the k-reciprocal sampling algorithm is used to construct a more comprehensive sample pair. The proposed framework has achieved state-of-the-art performance in CUHK-PEDES, which proves its great capacity and prospect. © 2022, Springer Nature Singapore Pte Ltd.

关键词： Network architecture

来源：评论

学校读者我要写书评

暂无评论

Exploration of Data Scene Characterization and 3D ROC Evaluation for Hyperspectral Anomaly Detection

引用

Remote Sensing 2024年第1期16卷

作者： Chang, Chein-I Chen, Shuhan Zhong, Shengwei Shi, Yidan Information and Technology College Dalian Maritime University Dalian116026 China Remote Sensing Signal and Image Processing Laboratory Department of Computer Science and Electrical Engineering University of Maryland BaltimoreMD21250 United States Department of Electrical Engineering National Cheng Kung University Tainan70101 Taiwan Department of Electrical Engineering Zhejiang University Hangzhou310027 China School of Computer Science and Engineering Nanjing University of Science and Technology Nanjing210094 China

Whether or not a hyperspectral anomaly detector is effective is determined by two crucial issues, anomaly detectability and background suppressibility (BS), both of which are very closely related to two factors, the datasets used for a selected hyperspectral anomaly detector and detection measures used for its performance evaluation. This paper explores how anomaly detectability and BS play key roles in hyperspectral anomaly detection (HAD). To address these two issues, we investigate three key elements attributed to HAD. One is a selected hyperspectral anomaly detector, and another is the datasets used for experiments. The third one is the detection measures used to evaluate the effectiveness of a hyperspectral anomaly detector. As for hyperspectral anomaly detectors, twelve commonly used anomaly detectors were evaluated and compared. To address the appropriate use of datasets for HAD, seven popular and widely used datasets were studied for HAD. As for the third issue, the traditional area under a receiver operating characteristic (ROC) curve of detection probability—PD versus false alarm probability, PF, (AUC(D,F))—was extended to 3D ROC analysis where a 3D ROC curve was developed to generate three 2D ROC curves from which eight detection measures could be derived to evaluate HAD in all round aspects, including anomaly detectability, BS and joint anomaly detectability and BS. Qualitative analysis showed that many works reported in the literature which claimed that their developed hyperspectral anomaly detectors performed better than other anomaly detectors are actually not true because they overlooked these two issues. Specifically, a comprehensive study via extensive experiments demonstrated that these 3D ROC curve-derived detection measures can be further used to address the various characterizations of different data scenes and also to provide explanations as to why certain data scenes are not suitable for HAD. © 2023 by the authors.

关键词： Curve fitting

来源：评论

学校读者我要写书评

暂无评论

Analysis of Video Quality Datasets via Design of Minimalistic Video Quality Models

arXiv

引用

arXiv 2023年

作者： Sun, Wei Wen, Wen Min, Xiongkuo Lan, Long Zhai, Guangtao Ma, Kede The Institute of Image Communication and Information Processing Shanghai Jiao Tong University Shanghai200240 China The Department of Computer Science City University of Hong Kong Kowloon Hong Kong The Institute for Quantum Information State Key Laboratory of High Performance Computing College of Computer Science and Technology National University of Defense Technology Changsha410073 China The Institute of Image Communication and Information Processing The MoE Key Lab of Artificial Intelligence AI Institute Shanghai Jiao Tong University Shanghai200240 China The Department of Computer Science The Shenzhen Research Institute City University of Hong Kong Kowloon Hong Kong

Blind video quality assessment (BVQA) plays an indispensable role in monitoring and improving the end-users’ viewing experience in various real-world video-enabled media applications. As an experimental field, the improvements of BVQA models have been measured primarily on a few human-rated VQA datasets. Thus, it is crucial to gain a better understanding of existing VQA datasets in order to properly evaluate the current progress in BVQA. Towards this goal, we conduct a first-of-its-kind computational analysis of VQA datasets via designing minimalistic BVQA models. By minimalistic, we restrict our family of BVQA models to build only upon basic blocks: a video preprocessor (for aggressive spatiotemporal downsampling), a spatial quality analyzer, an optional temporal quality analyzer, and a quality regressor, all with the simplest possible instantiations. By comparing the quality prediction performance of different model variants on eight VQA datasets with realistic distortions, we find that nearly all datasets suffer from the easy dataset problem of varying severity, some of which even admit blind image quality assessment (BIQA) solutions. We additionally justify our claims by comparing our model generalization capabilities on these VQA datasets, and by ablating a dizzying set of BVQA design choices related to the basic building blocks. Our results cast doubt on the current progress in BVQA, and meanwhile shed light on good practices of constructing next-generation VQA datasets and models. Code is available at https://***/sunwei925/***. Copyright © 2023, The Authors. All rights reserved.

关键词： Deep neural networks

来源：评论

学校读者我要写书评

暂无评论

FUNCTIONAL CONNECTIVITY VIA TOTAL CORRELATION: ANALYTICAL RESULTS IN VISUAL AREAS

arXiv

引用

arXiv 2022年

作者： Li, Qiang Steeg, Greg Ver Malo, Jesus Image Processing Laboratory University of Valencia Spain Georgia State University Georgia Institute of Technology Emory University AtlantaGA30303 United States Computer Science & Engineering University of California Riverside RiversideCA92507 United States Image Processing Laboratory University of Valencia Valencia46980 Spain

Recent studies invoke the superiority of the multivariate Total Correlation concept over the conventional pairwise measures of functional connectivity in biological networks. Those seminal works certainly show that empirical measures of Total Correlation lead to connectivity patterns that differ from what is obtained using the most popular measure, linear correlation, or its higher order and nonlinear alternative Mutual Information. However, they do not provide analytical results that explain the differences beyond the obvious multivariate versus bivariate definitions. Moreover, the accuracy of the empirical estimators could not be addressed directly because no controlled scenario with known analytical result was provided either. This point is critical because empirical estimation of information theory measures is always challenging. As opposed to previous empirical approaches, in this work we present analytical results to prove the advantages of Total Correlation over Mutual Information to describe the functional connectivity. In particular, we do it in neural networks for early vision (retina-LGN-cortex) which are realistic but simple enough to get analytical results. The presented analytical setting is also useful to check empirical estimates of Total Correlation. Therefore, once certain estimate can be trusted, one can explore the behavior with natural signals where the analytical results (that assume Gaussian signals), may not be valid. In this regard, as applications (a) we explore the effect of connectivity and feedback in the analytical retina-LGN-cortex network with natural images, and (b) we assess the functional connectivity in visual areas V1-V2-V3-V4 from actual fMRI recordings. © 2022, CC BY-NC-SA.

关键词： Information theory

来源：评论

学校读者我要写书评

暂无评论

Model Predictive Control Method for Multi-motor System with Dead Zone

Model Predictive Control Method for Multi-motor System with ...

引用

作者： Genglin Fan Xiuchuan Tang Yi Shen Linan Deng China-EU Institute for Clean and Renewable Energy Key Laboratory of Image Processing and Intelligent Control Huazhong University of Science and Technology School of Mechanical Science and Engineering Key Laboratory of Image Processing and Intelligent Control Huazhong University of Science and Technology School of Artificial Intelligence and Automation Key Laboratory of Image Processing and Intelligent Control Huazhong University of Science and Technology

The multi-motor system shows excellent performance in achieving high-precision control in the applications with large load inertia,such as large-aperture telescopes and highprecision processing machine ***,the non-linearity of gear transmission remains a key challenge that will cause the fluctuation of angular velocity and position of the load in the multi-motor *** order to compensate for the nonlinearity in the multi-motor system,this paper introduces a deadzone model into the spring-damper dynamics of the multi-motor system,based on which a model predictive control(MPC) method is proposed to control the angular velocity and angle of the *** optimization target of the proposed controller is to limit the fluctuations of input torque as much as *** effectiveness of the dead-zone based dynamic model and the MPC method are verified by simulation.

关键词： multi-motor system MPC dead zone

来源：评论

学校读者我要写书评

暂无评论

Zero-Sum Game Based Secure Tracking Control of UAV Against FDI Attacks Using Fixed-Time Convergent Reinforcement Learning

Zero-Sum Game Based Secure Tracking Control of UAV Against F...

引用

IEEE Conference on Decision and Control

作者： Zhenyu Gong Feisheng Yang Dongrui Wu Research & Development Institute of Northwestern Polytechnical University in Shenzhen School of Automation Northwestern Polytechnical University Xi'an China Key Laboratory of the Ministry of Education for Image Processing and Intelligent Control School of Artificial and Automation Huazhong University of Science and Technology Wuhan China

In this paper, a fixed-time convergent reinforcement learning (RL) algorithm is developed to realize the secure tracking control of the unmanned aerial vehicle (UAV) via the zero-sum game for the first time. To mitigate FDI attack on actuators that may cause the UAV to deviate from the reference trajectory, a zero-sum differential game framework is built in which the secure controller tries to minimize the common performance function, yet the attacker plays a contrary role. Obtaining the optimal secure tracking controller depends on solving the Hamilton-Jacobi-Isaacs (HJI) equation related to the zero-sum game. Therefore, a critic-only online RL algorithm is proposed that can converge in a fixed time interval, with the corresponding convergence proof provided. A simulation example is given to show the effectiveness of the raised method.

关键词：

来源：评论

学校读者我要写书评

暂无评论

AdaSemiCD: An Adaptive Semi-supervised Change Detection Method Based on Pseudo Label Evaluation

arXiv

引用

arXiv 2024年

作者： Ran, Lingyan Wen, Dongcheng Zhuo, Tao Zhang, Shizhou Zhang, Xiuwei Zhang, Yanning School of Computer Science Shaanxi Provincial Key Laboratory of Speech and Image Information Processing The National Engineering Laboratory for Integrated Aerospace-GroundOcean Big Data Application Technology The Ningbo Institute of Northwestern Polytechnical University Northwestern Polytechnical University Xi’an710072 China College of Information Engineering Northwest A&F University Yangling712100 China

Change detection(CD) is an essential field in remote sensing, with a primary focus on identifying areas of change in bitemporal image pairs captured at varying intervals of the same region. The data annotation process for CD tasks is both time-consuming and labor-intensive. To better utilize the scarce labeled data and abundant unlabeled data, we introduce an adaptive semi-supervised learning method, AdaSemiCD, to improve pseudo-label usage and optimize the training process. Initially, due to the extreme class imbalance inherent in CD, the model is more inclined to focus on the background class, and it is easy to confuse the boundary of the target object. Considering these two points, we develop a measurable evaluation metric for pseudo-labels that enhances the representation of information entropy by class rebalancing and amplification of ambiguous areas, assigning greater weights to prospective change objects. Subsequently, to enhance the reliability of samplewise pseudo-labels, we introduce the AdaFusion module, to dynamically identifying the most uncertain region and substituting it with more trustworthy content. Lastly, to ensure better training stability, we introduce the AdaEMA module, which updates the teacher model using only batches of trusted samples. Experimental results on ten public CD datasets validate the efficacy and generalizability of our proposed adaptive training framework. Copyright © 2024, The Authors. All rights reserved.

关键词： Self-supervised learning

来源：评论

学校读者我要写书评

暂无评论

Experimental Demonstration of a Hybrid Ofdma/Noma Scheme for Multi-User Underwater Wireless Optical Communication Systems

SSRN

引用

SSRN 2023年

作者： Chen, Danyang Zhang, Xue Fan, Kai Wang, Jianping Lu, Huimin Wang, Qingxuan Wu, Shuai Hao, Rui Li, Zhao Jin, Jianli School of Computer and Communication Engineering University of Science and Technology Beijing Beijing100083 China Beijing Key Laboratory of High-end Printing Equipment Signal and Information Processing Beijing Institute of Graphic Communication Beijing102600 China Shunde Innovation School of University of Science and Technology Beijing Foshan528399 China

In this work,a hybrid multiple access scheme for multi-user underwater wireless optical communication(UWOC) systems is proposed and presented. The scheme combines the respective advantages of orthogonal frequency-division multiple access(OFDMA) and non-orthogonal multiple access(NOMA) schemes to reduce the unfairness among users caused by the unique high-frequency fading characteristics of the underwater optical channel. Multi-verse optimizer(MVO) algorithm is further introduced for solving the nonlinear problem of user power allocation. Experimental results in different water quality environments demonstrate that the hybrid OFDMA/NOMA scheme with MVO effectively improves the communication performance of the established 4-user UWOC system compared to the pure NOMA scheme and the pure OFDMA scheme, and a system sum rate of 3.94 Gbit/s is achieved. © 2023, The Authors. All rights reserved.

关键词： Frequency division multiple access

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：